Band 8.5 model answer

Fish stocks in many of the world's most productive ocean regions have declined dramatically over recent decades, threatening both marine ecosystems and the food security of billions of people who depend on fish as a primary protein source. Identifying the causes of this collapse and proposing workable solutions is a matter of genuine urgency.

The root cause is the economic structure of commercial fishing, which creates powerful incentives to harvest as much as possible as quickly as possible. When a fish stock is a shared resource, as nearly all commercially significant stocks are, any individual vessel that exercises restraint simply leaves fish for competitors to take, creating a classic 'tragedy of the commons'. This incentive structure is amplified by government subsidies, estimated in aggregate at tens of billions of dollars annually, which keep economically unviable fishing fleets operational and allow them to pursue ever-more-depleted stocks across distant oceans. Illegal, unreported and unregulated fishing, which is particularly prevalent in waters with weak enforcement capacity, adds further untracked pressure on populations that official data already show to be in serious decline.

Correcting these incentives requires coordinated international action. Science-based catch limits, established by independent bodies rather than by governments subject to fishing-industry lobbying, provide the necessary foundation. Marine protected areas, zones where commercial fishing is entirely prohibited, allow breeding populations to recover and have produced measurable stock increases wherever they have been rigorously enforced, as demonstrated by results in New Zealand and Palau. Reforming and redirecting fishing subsidies towards monitoring, enforcement and the economic transition of dependent coastal communities removes the financial scaffolding that sustains over-capacity. Finally, consumer-facing certification schemes such as the Marine Stewardship Council label create market pressure that rewards sustainable fishing practices.

These measures are individually insufficient but collectively capable of reversing the decline, provided political will keeps pace with the scale of the ecological and economic stakes.